Why do gun control advocates continue to reveal their ignorance about guns?

A couple of days ago, we saw Colorado Congresswoman Diana DeGette make a fool of herself talking about bullets and magazines. Now we have the president himself saying that the children murdered at Newtown were gunned down by a "fully automatic weapon."
President Obama told a group of Democratic donors Wednesday night that the children killed in the Newtown, Conn. attack last December were shot with a "fully automatic weapon."
Speaking to donors at a Democratic Congressional Campaign Committee fundraiser in San Francisco, Obama urged the need for "gun control," and referred for the first time to an alleged "fully automatic weapon" involved in the Sandy Hook Elementary School shooting, which took the lives of 20 children and 6 adults.
From the White House transcript (emphasis added):
Now, over the next couple of months, we've got a couple of issues: gun control. (Applause.) I just came from Denver, where the issue of gun violence is something that...(Read Full Post)